It is well known in the area of motor vehicle safety to provide a motor vehicle with an inflatable air bag deployment system which is activated by acceleration sensors in order to protect against the frontal impact of a driver or passenger against the steering and/or dashboard area of the vehicle in the event of an accident of the appropriate severity, particularly head-on collisions. Inflatable air bags are particularly beneficial in reducing head and chest injury since the air cushion offered by the inflated air bag stops a fast moving passenger in a soft, resilient and relatively recoil free manner.
These known types of inflatable air bag deployment systems are typically limited to implementation in the steering wheel or dashboard area of a motor vehicle. Accordingly, their safety benefits are only realized in the event of a front end collision.
For side collisions, the typical driver's side and/or passenger's side airbag does not provide adequate protection for passenger head impact against a side window. Thus, substantial head injuries may be incurred since the safety glass of the side window normally does not break by a blunt head impact and instead remains as a rigid, non-yielding wall. Accordingly, it is desirable to provide a means for protecting the passenger's head from harmful impact against a side window during a side collision.
It is known in the art to open an emergency exit for vehicle passengers by breaking a safety glass pane of a vehicle. For example, railroad cars and buses are often equipped with specially adapted safety hammers which are placed in tear-off holders adjacent to a window pane region for window egress in the event of an emergency. However, in view of the need for manual intervention by the user, it is clearly evident that these safety hammers do not permit the quick, near instantaneous breaking of a window prior to head impact during a side collision.
It is also known in the art to mount an explosive charge adjacent a front windscreen frame member of a motor vehicle and whereby the explosive charge is detonated to release outward or pop open the windshield from its frame member during an impact of the appropriate severity. In this way the passenger's head is prevented from impacting the front windshield. The explosive charge is controlled by electric switch operation and is connected in series with the vehicle battery.
While blasting away the front windshield may be an effective way to prevent a passenger's head from front windshield impact, the problems of head recoil and neck whiplash are still present. Moreover, it is not desirable in all instances to totally remove the windshield as it provides a shield against otherwise unobstructed entryway for flying objects, fire, smoke, gas or harmful vapors which may result during a vehicle collision.
Accordingly, there is an urgent need in the art for a motor vehicle safety device for protecting a passenger's head against harmful side window impact during a side collision, or sufficiently violent oblique collisions which result in the passenger(s) being tossed around inside the car and in that random movement striking the side window(s). There is a need for a safety device which breaks a vehicle side window during a side collision in a controlled manner to provide a soft, resilient cushion for a passenger's head so that the risk of head injury is substantially reduced. Finally, there is a need for such a safety device which is of low cost to manufacture and is easily implemented in existing vehicle designs.